Building closure assemblies of current design, such as patio doors, typically require up to six crews to form the butt joint at each corner of the door frame. Alignment and assembly at the four corners of the frame can be a laborious and costly operation. It is a general object of the present disclosure to provide a butt joint for a building closure assembly that can be economically fabricated and yet form a rigid frame with a good seal at each butt joint against water infiltration.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A closure assembly in accordance with one aspect of the present disclosure includes a frame having at least one hollow end rail and a pair of side rails coupled in butt joints to opposed ends of the end rail. The butt joints include a core extending through the hollow end rail and from opposed ends of the end rail through openings in the side rails into the interiors of the side rails. A saddle within each side rail interior straddles a corresponding end of the core. A fastener extends through each of the saddles into engagement with a corresponding end of the core firmly to clamp to side rails against opposed ends of the end rail. The core preferably is of uniform cross-section throughout its length, having edges that internally engage the hollow end rail against lateral movement of the core within the end rail. A resilient washer preferably is captured in compression between each saddle and the opposing end of the core. One of the saddles preferably has an integrally formed extension within one of the side rails for securement of a hinge to the side rail.